With the wide spread of electronic appliances including laptop computers, cellular phones, etc., there has recently been a rapid increase in demand for secondary batteries. A secondary battery is composed of an anode, a cathode, an electrolyte, and a separation membrane. Manganese oxides are widely used as main materials for the cathode. Demand for secondary batteries is now rapidly increasing, with the consequent increase in materials necessary for the production of secondary batteries.
Manganese sulfate monohydrate (MnSO4.H2O) is one of main cathode active materials for secondary batteries.
However, almost all the amount of manganese sulfate monohydrate needed as an electrode material for secondary batteries is imported. In addition, it is difficult to discover patent documents to which reference is made with regard to the production of manganese sulfate monohydrate from low-purity manganese ores or manganese-containing dust.